Gamma Hydroxybutyrate

DESCRIPTION

SUBSTANCE NAME

USES

This substance may be used either therapeutically but can also be subject to abuse.

Treatment for narcolepsy

Treatment for alcoholism

Anesthetic agent

Euphoric

“Date rape” agent

“Growth Hormone booster”

“Aphrodisiac”

“Muscle builder” (although effectiveness has never been proven)

INTERVENTION CRITERIA

The correct identification of the substance is important. If the symptoms are inconsistent with those described in the literature, or the history is considered unreliable, other substances may need to be considered.

Intervention Level

Child

Medical assessment and observation is recommended for:

- Any suspected ingestion in children

The risks of decontamination outweigh any benefits, and should not be attempted.

Adult

Medical assessment and observation is recommended for:

- Any suspected ingestion

- Exposures with intent to self-harm

The risks of decontamination outweigh any benefits, and should not be attempted.

History of dose ingested is not a reliable guide to management.

Observation Period

Observation at Home

All patients require medical attention.

Medical Observation

If medical observation is required the patient must be monitored for 6 hours following exposure for onset or worsening of symptoms.

If the patient is asymptomatic at the end of the observation period, and provided that appropriate assessment and investigations have been carried out, they may be:

Discharged into the care of a reliable observer, or

Referred for psychological assessment if the overdose or exposure was with intent to self-harm

Investigations

Levels

Serum concentrations do not aid management.

Monitoring

Monitor:

Level of consciousness

Heart rate

Blood pressure

Respirations

Seizure activity

Admission Criteria

Admission to an intensive care environment is recommended for patients who develop significant signs of toxicity including:

CNS depression requiring intubation

Respiratory depression

Aspiration pneumonitis

Hemodynamic instability

TREATMENT

TREATMENT SUMMARY

Emergency stabilization may be required for respiratory depression and/or pulmonary aspiration, immediate assessment and management of respiratory compromise is a priority. Due to fast onset of action, gastrointestinal decontamination is not recommended.

There is no proven antidote for poisoning. Extracorporeal elimination techniques would not be anticipated to be of clinical benefit in the majority of patients as most will satisfactorily recover with adequate airways management alone.

Supportive care is the mainstay of management, with primary emphasis on airway management and cardiovascular support. Airway protection including endotracheal intubation and/or assisted ventilation may be necessary due to respiratory depression and aspiration risk. Seizures may rarely occur and, in the presence of coma, indicate anoxia: manage the airway and ensure adequate ventilation. Should repetitive seizure occur in a well ventilated patient treat with a benzodiazepine, or if still refractory, a barbiturate. Myoclonic jerking is a recognized re-emergence phenomenon and single episodes do not require treatment. Other complications such as bradycardia, hypotension, hypothermia, and gastrointestinal upset should be treated along usual guidelines.

A withdrawal syndrome is recognized after chronic abuse of this compound and may last 3 to 21 days. Benzodiazepines are usually effective to relieve symptoms. Weakness, headache, fatigue and nausea lasting 3 days after ingestion may occur. However, if significant CNS depressant effects persist beyond 8 hours, alternative causes should be investigated.

ANTIDOTE(S)

There Are No Antidotes For This Substance

Agents including naloxone, flumazenil, and physostigmine have been investigated as potential antidotes. None have shown consistent results in reversing intoxication.

Physostigmine is viewed as an unproven experimental antidote for this intoxication. It was initially investigated as a reversal agent in patients under GHB-induced anesthesia.[2][3] However, use following poisoning has produced differing results, with the majority of patients not showing response.[4][5][6] Reviews of the literature have shown there is not sufficient evidence to support the use of physostigmine in acute GHB overdose.[6][7] At this stage physostigmine is not recommended.[1]

Additionally, naloxone and flumazenil have been used following human poisoning, both have had limited effect on reversing toxicity.[8][9][10][11][12] Neither of these compounds can be recommended.[1]

SIGNS AND SYMPTOMS

The correct identification of the substance is important. If the symptoms are inconsistent with those described in the literature, or the history is considered unreliable, other substances may need to be considered.

Other drug/compounds are commonly co-ingested with this substance and may significantly influence the clinical picture.[1]

With mild toxicity, gastrointestinal upset may occur and CNS effects predominate including CNS depression, euphoria, ataxia, disorientation, dizziness, and occasionally miosis and nystagmus. Sudden drowsiness followed by profound coma is a characteristic presentation; a GCS of 3 is not uncommon. Recovery is sometimes accompanied by emergence phenomena including myoclonic jerking, transient confusion, and agitation and combativeness.[1]

With severe toxicity, sudden, profound coma, seizures, and respiratory arrest may occur. Further complications may include bradycardia, hypotension, and hypothermia. Deaths are reported.[1][13][14][15]

Persistent symptoms of weakness, headache, fatigue, and nausea lasting three days after ingestion has been noted,[16] and a withdrawal syndrome is described.[17][18]

Onset/Duration of Symptoms

In the majority of cases signs and symptoms develop within 1 hour of ingestion and resolve within 4 to 8 hours of onset.[8][19][20][21][22][23] Recovery from coma, if it occurs, is typically rapid, and may be indicated by initial GCS score.[19] Weakness, headache, fatigue, and nausea lasting three days after ingestion has been noted.[16]

A withdrawal syndrome which may begin within 1 to 12 hours of the last dose and may continue for 3 to 21 days is described.[17][18][24][25][26][27]

Disclaimer

All information contained on this database is as accurate and up-to-date as our resources allow. Since the University of Otago, the New Zealand National Poisons Centre and Intergen cannot anticipate or control the conditions under which this information may be used, each user should view the information in the specific context of the intended application.

The University of Otago, the New Zealand National Poisons Centre and Intergen will not be responsible for damages of any nature resulting from use or reliance upon this information.